You don’t have to see a mouse to know there’s a problem. In fact, most homeowners never spot the actual mouse until the infestation is already established. Mice are small, fast, and excellent at hiding inside walls, attics, basements, and crawlspaces.

But they do leave evidence… and if you know what to look for, you can catch the infestation early — before the damage adds up.

Here are the top signs you have a mouse infestation (before you actually see one).

1. Small Droppings in Hidden Areas

Mouse droppings are the most common early warning sign.
They are tiny — about the size of a grain of rice — and pointed at both ends.

Look for droppings:

In kitchen cabinets
Under sinks (especially near plumbing penetrations)
Behind appliances like the stove or fridge
Along baseboards or inside pantries

Fresh droppings are dark and soft; older ones look gray and crumbly.

If you start noticing new droppings daily, that usually means mice are nesting nearby.

2. Scratching Noises in Walls or Ceilings

Hear scratching late at night? You’re not imagining it.

Mice are nocturnal, and you’ll typically hear:

Light scratching
Scurrying
Occasional squeaks

Most noises come from walls, ceilings, attics, or under floorboards.

A single mouse doesn’t make much noise… but an infestation does.

3. Grease Marks on Baseboards and Walls

Mice navigate by following the same pathways every night. As they squeeze along walls and tight spaces, the oils in their fur rub off.

If you see:

Smudges
Dark streaks
Greasy marks

… especially along baseboards or tight areas, that’s a red flag.

These marks become more noticeable as the infestation grows.

4. Chew Marks on Food Packaging or Cords

Mice constantly chew — not because they’re hungry, but because their teeth never stop growing.

Common chew locations:

Dog food bags
Cardboard pantry boxes
Plastic containers
Electrical wiring (yes, really)

Chewed wires are more than a nuisance — they are one of the leading causes of house fires started by rodents.

5. Strange or Musty Odors

Mouse urine has a sharp, ammonia-like smell.
If the infestation is larger, the odor becomes noticeable — especially in areas with limited airflow like closets, attics, or crawlspaces.

Pets often notice the smell before humans do. If your dog or cat suddenly starts circling one spot or pawing at a wall, that could be a sign.

6. Nesting Materials in Random Places

Mice build nests from anything they can shred:

Insulation
Paper
Cardboard
Dryer lint
Cotton or fabric scraps

If you find small piles of shredded material in unusual places, a nest is likely close.

Don’t Wait Until You See a Mouse — Stop the Infestation Early

Seeing any of these signs means mice are already inside your home. The longer they’re there, the faster they breed — and the harder they are to remove.

Let the professionals take it from here.

Contact Uinta Pest Solutions today at (801) 290-8619 for fast, effective mouse removal and prevention. We eliminate current infestations and seal entry points to stop mice from coming back.

📞 Protect your home. Protect your family. Call Uinta Pest Solutions now.

Top Signs You Have a Mouse Infestation (Before You Actually See One)